Commercial blood glucose sensors available for diabetics are chemical sensors based on the enzyme glucose oxidase which breaks down glucose, in the presence of oxygen, into hydrogen peroxide. The produced hydrogen peroxide reacts with either electrical or optical molecules, producing a change proportional to the amount of glucose within the blood volume. These commercial sensors may have an error of less than 15 mg/dL blood glucose concentration. They, however, have the disadvantage of requiring blood from the patient through either a forearm or finger prick, resulting in pain to the patient and also a potential risk of infection. It has been shown that the pain and embarrassment associated with repeated finger pricking results in low patient compliance.